WASHINGTON – President Bush, in a much-anticipated speech to the nation last night, put forth his new plan for winning the war in Iraq, telling the American people: “We can and we will prevail.”

In a dramatic shift of war-fighting policy, the president ordered 21,500 additional U.S. forces into Iraq to break the current cycle of violence and “hasten the day our troops begin coming home.”

It was Bush’s first prime-time address from the White House library instead of the Oval Office. He stood behind a podium, with shelves of books visible in the background, and outlined a new strategy that includes:

Democrats immediately pounced on the plan as the worst move possible, but it seemed unlikely they’d be able to stop it.

“The situation in Iraq is unacceptable to the American people – and it is unacceptable to me,” the president said in his 20-minute speech.

“Our troops in Iraq have fought bravely. They have done everything we have asked them to do. Where mistakes have been made, the responsibility rests with me.”

It was the first time the president had admitted errors in the conduct of the war.

“Our past efforts to secure Baghdad failed for two principal reasons: There were not enough Iraqi and American troops to secure neighborhoods that had been cleared of terrorists and insurgents. And there were too many restrictions on the troops we did have,” he added.

“In earlier operations, political and sectarian interference prevented Iraqi and American forces from going into neighborhoods that are home to those fueling the sectarian violence. This time, Iraqi and American forces will have a green light to enter these neighborhoods.”

Bush said Iraqi Prime Minister Nuri al-Maliki has pledged that “political or sectarian interference will not be tolerated.”

Hours before Bush announced plans to take the handcuffs off U.S. troops, Maliki ordered cleric Muqtada al-Sadr’s renegade Shiite militia to surrender their arms or face an all-out assault by U.S.-backed Iraqi forces.

After months of consultation with the Pentagon and State Department, and the blue-ribbon Iraq Study Group led by former Secretary of State James Baker, Bush said, “One message came through loud and clear: Failure in Iraq would be a disaster for the United States.”

“The consequences of failure are clear: Radical Islamic extremists would grow in strength and gain new recruits. They would be in a better position to topple moderate governments, create chaos in the region, and use oil revenues to fund their ambitions. Iran would be emboldened in its pursuit of nuclear weapons.

“Our enemies would have a safe haven from which to plan and launch attacks on the American people. On September the 11th, 2001, we saw what a refuge for extremists on the other side of the world could bring to the streets of our own cities. For the safety of our people, America must succeed in Iraq.”

Addressing his war critics, including most Democrats on Capitol Hill, Bush said, “We concluded that to step back now would force a collapse of the Iraqi government, tear that country apart, and result in mass killings on an unimaginable scale. Such a scenario would result in our troops being forced to stay in Iraq even longer, and confront an enemy that is even more lethal.”

And he spoke directly to the American people, saying, “Fellow citizens: The year ahead will demand more patience, sacrifice and resolve. It can be tempting to think that America can put aside the burdens of freedom. Yet times of testing reveal the character of a nation. And throughout our history, Americans have always defied the pessimists and seen our faith in freedom redeemed.

“The challenge playing out across the broader Middle East is more than a military conflict. It is the decisive ideological struggle of our time.”

Bush, who rejected the Baker panel’s recommendation to enlist help from Syria and Iran, singled out the two terrorist-supporting nations for fanning the flames of violence in Iraq – and pledged to “seek out and destroy” their networks aiding the insurgents.

The president put the onus on Iraqis to take the lead in the fighting and rebuilding their country – although he stopped short of laying out specific consequences if they fail.

To motivate Iraqi leaders, the president pledged to turn over security in all 18 provinces to Iraqi forces by the end of the year. They currently have responsibility for three.

Bush said the infusion of economic aid is critical to rebuilding Iraqis infrastructure – and the morale of its citizens.

But he lowered expectations for Americans about what success in Iraq will look like.

“Victory will not look like the ones our fathers and grandfathers achieved. There will be no surrender ceremony on the deck of a battleship,” he said.

The president’s plans will gradually flood Baghdad with five brigades of about 17,500 soldiers, supplementing the 132,000 troops already in Iraq.

The first unit to be deployed, the 2nd Brigade of the 82nd Airborne Division now stationed in bordering Kuwait, will have their boots on the ground in Baghdad by Monday.

The second brigade will follow on Feb. 15, with the following brigades coming in waves every 30 days. An advance contingent of 90 troops from the 82nd Airborne arrived in Baghdad yesterday, with 100 more expected today, ABC News reported last night.

Bush is also dispatching 4,000 Marines, to be deployed in two waves, into the violent Anbar province, a hotbed of al Qaeda insurgents.

“A captured al Qaeda document describes the terrorists’ plan to infiltrate and seize control of the [Anbar] province. This would bring al Qaeda closer to its goals of taking down Iraq’s democracy, building a radical Islamic empire, and launching new attacks on the United States at home and abroad,” Bush said.

“America’s men and women in uniform took away al Qaeda’s safe haven in Afghanistan – and we will not allow them to re-establish it in Iraq.”

Secretary of Defense Robert Gates received Bush’s order for more troops yesterday, and intended to make it official by signing the request this morning.

Other units, including Marine brigades in western Iraq, could be asked to extend their deployments.

Bush’s plan demands Iraqis commit three brigades to Baghdad – all to be deployed by Feb. 15.

He said Baghdad will be split into nine military districts, with an Iraqi commander and his troops in charge of each section, and American advisers close by. The expanded number of U.S. troops embedded with Iraqi security forces will provide on-the-job training and ensure combat effectiveness.

And as U.S. and Iraqi forces sweep into insurgent strongholds, they’ll use the added manpower to hold the region after terrorists are driven out – blocking the enemy from slipping back in.

“In earlier operations, Iraqi and American forces cleared many neighborhoods of terrorists and insurgents – but when our forces moved on to other targets, the killers returned. This time, we will have the force levels we need to hold the areas that have been cleared,” Bush said.

He called for $414 million to expand provincial reconstruction teams and $400 million more in quick-response funds to address civilian problems, such as soaring unemployment.

An additional $350 million will be doled out to ground commanders to cut through bureaucratic red tape and solve local problems quickly.

Bush is submitting to Congress a $6.5 billion tab to pay for the troop push and reconstruction – sure to spark a battle on Capitol Hill, where Democrats are decrying the plan as an all-but-certain ill-fated escalation of the war.

Bush also demanded the Iraqi government commit $10 billion of its own money for reconstruction.